Chap 8 Flashcards
What are 3 principles of the sensory system?
- Sensory receptors respond to distinct stimuli within the environment
- Sensation is different than perception
- Without sensory feedback the motor functions cannot function
Describe energy transduction for each sense
- Vision: light energy is turned into chemical energy by the retina
- Auditory: sound waves are turned into mechanical energy in the ear
- Somatosensory: mechanical energy from touch or pressure is turned into action potentials
- Taste and olfaction: chemical molecules in the air or on food act on these receptors
What are the 7 subsystems of the visual pathways
- the superchiasmic nucleus
- pretectum
- pineal gland
- superior colliculus
- accessory optic nucleus
- visual cortex
- frontal eye fields
What are rods versus cones ?
Rods: sensitive to levels of light
Cones: sensitive to wavelengths that produce color perception
What is the main visual pathway in the brain ?
The main pathway starts at the retina, projects to the lateral geniculate nucleus (LGN) of the thalamus that then relays info to the visual/striate cortex
What is the secondary visual pathway ?
The tectopulvinar pathway: starts at the eyes, projections go to the superior colliculus, then to the pulvinar in the thalamus
What is the geniculostriate pathway responsible for ?
patterns, colors and movements
What is the tectopulvinar pathway responsible for ?
detecting and orienting to visual stimuli
What are the 6 steps of sound waves moving through the ear ?
- the pinna of the outer ear catches sound waves and moves them into the ear canal
- the waves are amplified which makes the ear drum vibrate
- this vibration moves to the ossicles (the hammer, anvil and stirrup)
- vibration amplification occurs again, moving to the oval window
- the waves continue through the cochlear fluid
- this cases the basilar membrane and the tectorial membrane to bend and produced neural activity
How are sound waves transduced into neural impulses ?
different frequencies cause different areas of the basilar membrane to resonate
Describe the auditory pathway in 5 steps
- Starts in the ventral & dorsal cochlear nucleus
- Connections are sent to the olivary complex and trapezoid body
- Continues to the inferior colliculus
- Reach the geniculate nucleus
- Reaches the auditory cortex
What are the 3 classifications of somatosensory receptors?
- Nociception
- Hapsis
- Proprioception
Describe nocicpetion
perception of pain, temperature or itch coming from free nerve endings
Describe hapsis
discriminating objects based on touch though stimulation of the hair or skin tissue
Describe proprioception
perception of body location and movement
What are the 2 somatosensory pathways to the brain
- haptic-proprioception: signals travel ipsilateraly to the primary motor cortex
- nociceptive: signals travel contralaterally along the spin thalamic tract
